Device for clamping workpieces



Nov. 18, 1941. J. HOZA 2,263,130

' DEVICE FOR GLAMPING WORKPIECES Filed Feb. 10, 1940 FIG 2 Patented Nov. 18, 1941 UNITED STATES PATENT OFFICE DEVICE FOR CLAMPING WORKPIECES John Hoza, New York, N.Y.

Application February 10, 1940,Scrial No. 318,348 In Czechoslovakia October 6, 1938 Claims. (c1. 1-32) The subject of the present invention is a device for clamping together work-pieces, for instance heels to shoes or boots (hereinafter and in the claims referredto simply as shoes when nailing them together.

Previouslyknown devices of this kind have usually involved laborious operations by the operator, while during the nailing operation the clamping tended repeatedly to release. The solution of these problems has proved difiicult. The chief object of the present invention is to overcome or mitigate these disadvantages.

Further objects and features of the present invention will be apparent from the following description and the accompanying drawings, in which a clamping device according to the invention for a heel-attaching machine is illustrated by way of example, and in which:

Fig. 1 is a part sectional side elevation of the clamping device in the vertical position-before the device is set in operation, and

i Fig. 2 is a plan view thereof.

In the construction illustrated there is pivotally attached at the end of the plunger I by means of the pivot 2 an arm 3 carrying a workreceiving die head comprising a holder 1 and a die 9. 'A support 4 with a downwardly extending pin 5 is adapted to slide in a slot in the arm 3, and a hand lever arm 6 for pivoting the clamping head is firmly attached to this support 4. On the pin 5 there is loosely mounted the holder I which carries, by means of a pin 8, the removable die 9, which is secured against falling.

out by means of a screw II]. A screw II passes on one side through thedie holder 1 and projects into a groove in the pin 5 of support 4, so as to guide, and to prevent the falling out of, the holder and its die. If a shoe with the heel is not pushed onto the die 9, the screw II strikes the bevelled part or stop I2 which is inserted into a transverse opening in the pin 5 and is positioned in the longitudinal groove of the lat- The die holder I is retained normally in the upper position in which it is shown onthe support 4 and pin 5 thereof by a pawl I5. On the left-hand side of the holder I a plate spring I4 attached by means of a screw I3 presses on the pawl I 5 which is pivoted on a pivot I6 in a recess in the holder I and which engages with a projection of the support 4 so as to maintain the holder and die in the upp r position. By means of screws I1 the support 4 carries on both sides vertical cover plates I8 which serve to prevent damage to the shoe upper when the parts are pressed together, and an aperture is provided to permit the free passage of a pin or rod l9, one end of which extends to the pawl I5 Whilstthe other end is provided with a ball and projects I into the opening of a lug 20 forming part of the hand lever 6. The lug 20 is attached to one end of a two-part push rod 2| which projects through the guide 22 and engages in a guide in the lever 5. A knob 33 attached to this end of 1 the push rod engages in a longitudinal recess in the lever 6, in whichis mounted a spring 23 adjustable in tension by means of the nut 24. I

The support 4 with the attached hand lever arm 6 can be shifted in the slot.of the arm 3 l by means of the screw 25 for the purpose of adjusting the die 9 relatively to the nailing head according to the type of shoe being dealt with. The die is adjustable in position in accordance with the more or less oblique surface of the workpieces by means of the regulating screw 26, which is locked by the set screw 2'! carried in the plunger I. The arm 3 has a screwed-on bracket 28 for one end of a spring 29, whose other end is anchored to a, holder 3|] on the plunger I. There is also provided at the end of the plunger a holder 3| for the powerful spring 32 for the return of the plunger.

The manner in which the device operates is as follows: Before the shoe with the heel is positioned on the removable die 9, the arm 3, with the release head and the release device, is swung upwards about the pivot 2 by the spring 29, i. e. inclined towards the operator. After the work has been positioned accurately the hand lever arm 6 is pulled down against the action of the weak spring 29, so that the arm 3 and the release head 1, 9 are moved into vertical working alignment above the nailing head with the plunger, the, position of alignment being determined by contact of the arm 3 with the previously adjusted screw 25 in plunger I. When this position is reached the release device is set in operation by pressing the knob 33 of the rod 2I against the spring 23, whereby the rod moves in its guide towards the left, i. e. towards the interior of the machine. The lug 20 of the push rod then strikes the ball of rod I9 so that the other end of this latter rod releases the pawl I5 from the projection of support 4, with the result that the holder 1 with the die and the work drops onto the head of the nailing machine 1. e. the operative position. In this way a gap is formed between the support 4 and. the holder 1, but this is covto adjust the shoe so that the heel falls exactly into the nailing head, since the die with its holder is completely free in this released position prior to the nailing operation. The strain on the operator is very small, because it is only necessary to overcome the force of a very small and weak spring 29. When the shoe is positioned with the heel on the nailing head the operator presses a pedal (not shown), whereby a motor lowers the plunger with the entire upper mechanism until the latter contacts with the released and lowered die head, so that the latter is now pressed against the work by the motor power. When this operation has been effected and the work-pieces have been pressed together to the desired extent, they are nailed together. At the same time the pawl l5 snaps into engagement with the projection of support 4 when the arm 3 is lowered, and thus presses the rod IS with its ball into the recess in the lug 20 of the push rod 2|, which, when the knob 33 is released, is returned by the tension of spring 23 and thus ensures once, more the locking of the clamping head to the arm 3, so that after the nailing operation all the parts of the clamping device are returned by means of the powerful spring 32, to the initial upper position, the spring 29 swinging the whole clamping device up into the oblique position to permit the positioning of further work-pieces, whereupon the process is repeated.

It will be clear that the support arm 3, 4, the holder 1 and die 9 thereon and the laterally extending operating arm 6 together constitute a two-arm lever structure which is fulcrumed at Z to the power-operable plunger I, and that it is by virtue of this structure that the operator applies leverage to the arm 6 in order to press the parts 3, 4 and 8 into working alignment with the plunger l against the return force of the light spring 29.

I claim:

1. A device for clamping workpieces, e. g. heels to shoes when nailing them together, compris-v ing in combination, a work-engaging die, a die support on which said die is slidably mounted said die support and the die therewith being swingable into operative alignment againstthe action of relatively weak return means, means for releasably retaining said die in an upper inoperative position on said support, means for releasing said retaining means so that the die can slide into the operative position, means for applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again, said die support being swingable manually into operative alignment and provided with a projecting manual control for actuating said releasing means, power means for applying pressure to the die, relatively strong return means against which said power means acts and which returns the device to the initial raised position.

2. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a diesupport on which said die is slidably mounted saiddie support and the die therewith being swingable into operative alignment against the action of relatively weak return means, a vertically reciprocable power-driven plunger on which said support is pivotally mounted, and adjustable stop means on said plunger which is adapted to maintain said support in the operative alignment, means for releasably retainingsaid die in an upper inoperative position on said support, means for releasing said retaining means so that the die can slide into the operative position, said plunger applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again, said die support being swingable manually into operative alignment and provided with a projecting manual control for actuating said releasing means.

3. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a diesupport on which said die is slidably mounted said die support and the die therewith being swingable into operative alignment against the action of relatively weak return means, means for releasably retaining said die in an upper inoperative position on said support, means for releasing said retaining means so that the die can slide into the operative position, a swingable arm on which said support is slidably adjustable and by means of which said support swings, said releasing means being mounted on said arm, means for applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again.

4. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a diesupport, on which said die is slidably mounted said die support and the die therewith being swingable into operative alignment against the action of relatively weak return means, a holder for said die, and pin and groove means by which the holder is slidable on said support, a, pawl carried by said holder and adapted releasably to engage said support to retain said holder and die in an upper inoperative position on said support, means for releasing said pawl so that the die and holder can slide into the operative position, a stop adapted to prevent the holder sliding entirely ofi the support, a swingable arm on which said support is slidably adjustable and by means of which said support swings, said releasing, means being mounted on said arm, means for applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again.

5. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a die-support on which said die is slidably mounted said die support and the die therewith being swingable into operative alignment against the action of relatively weak return means, a holder for said die, and pin and groove means by which the holder is slidable on said support, a pawl carried by said holder and adapted releasably to engage said support to retain said holder and die in an upper inoperative position on said support, means for releasing said pawl so that the die and holder can slide into the operative position, a stop adapted to prevent the holder sliding entirely ofi the support, a swingable arm on which said support is slidably adjustable and by means of which said support swings, said releaslng meansv being mounted on said arm, means for applying pressure to the die through said support while. the former is in the operative position whereby said retaining means automatically retains the die on the support again, cover sheeting extending downwardly from said support around said holder to bridge the gap formed between support and holder when the latter slides to the operative position, whereby damage to the work may be prevented.

6. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a diesupport on which said die is slidably mounted said die support and the die therewith being swingable into operative alignment against the action of relatively weak return means, a vertically reciprocable power-driven plunger on which said support is pivotally mounted, and adjustable stop means on said plunger which is adapted to maintain said support in the operative alignment, means for releasably retaining said die in an upper inoperative position on said support, means for releasing said retaining means so that the die can slide into the operative position, means for applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again, said die support being swingable manually into perative alignment and provided with a projecting manual control for actuating said releasing means, cover sheeting extending downwardly from said support around said holder to bridge the gap formed between support and holder when the latter slides to the operative position whereby damage to the work may be prevented.

'7. A device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a work-engaging die, a die-support on which saiddie is slidably mounted said die support and the die therewith being swingable into operative alignment against the action of relatively weak return means, means for releasably retaining said die in an upper inoperative position on said support, means for releasing said retaining means so that the die can slide into the operative position, a swingable arm on which said support is slidably adjustable and'by means of which said support swings, said releasing means being mounted on said arm, means for applying pressure to the die through said support while the former is in the operative position whereby said retaining means automatically retains the die on the support again, cover sheeting extending downwardly from said support around said holder to bridge the gap formed between support and holder when the latter slides to the operative position whereby damage to the work may be prevented.

8. Device for clamping work pieces, e. g. heels to shoes when nailing them together, comprising in combination, a die carrier, a downwardly extending support on which said carrier is slidable by pin and groove means, a pivotal mounting and a projecting manual operating arm for said support adapted to actuate same into operative alignment about said pivotal mounting said support being laterally slidably adjustable in said arm, resilient means against which said support is actuated into operative alignment, resilient pawl means mounted in a recess in said carrier and adapted releasably to secure said carrier to said support, push-rod mechanism operable by a manual control on said operating arm for releasing said pawl to allow the die carrier to drop towards the work, said pawl means auto matically re-securing said carrier to said support when the device applies pressure downwardly on the work.

9. In a heel-attaching machine, a power-operable plunger and a lever structure fulcrumed on said plunger, said lever structure comprising a dependent support arm, a die holder mounted on said arm for down-and-up movement from and to an upper position thereon, a pawl for retaining said die holder in the upper position, a laterally extending lever arm by means of which the operator can apply leverage to said lever structure and in this way pivotally force said support arm and die holder into working alignment with said plunger, and a device for releasing said pawl to permit the downward movement of the die holder, said device extending from the pawl along said lever arm for actuation there by the operator.

10. In a heel-attaching machine, a power-operable plunger, a lever structure fulcrumed on said plunger, said lever structure comprising a dependent support arm, a die holder mounted on said support arm for down-and-up movement from and to an upper position thereon and a laterally extending lever arm by means of which the operator can apply leverage to said lever structure and in this way pivotally force said support arm and die holder into operative alignment with said plunger, and a return spring connecting said lever structure to said plunger and acting upwardly in opposition to the applied leverage.

JOHN HOZA. 

